Metoprolol Tartrate and Hydrochlorothiazide

1 INDICATIONS AND USAGE Metoprolol tartrate and hydrochlorothiazide tablets are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure lowers the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including metoprolol. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than 1 drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Metoprolol tartrate and hydrochlorothiazide tablets may be administered with other antihypertensive agents. Limitation of Use Metoprolol tartrate and hydrochlorothiazide tablets are not indicated for initial therapy of hypertension. If the fixed combination represents the dose titrated to the individual patient’s needs, therapy with the fixed combination may be more convenient than with the separate components. Metoprolol tartrate and hydrochlorothiazide tablets are the combination tablet of metoprolol tartrate, a beta adrenoceptor blocker and hydrochlorothiazide (HCTZ), a thiazide diuretic, indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. (1)

DOSAGE AND ADMINISTRATION Dosage should be determined by individual titration (see INDICATIONS AND USAGE). Hydrochlorothiazide is usually given at a dosage of 12.5 to 50 mg per day. The usual initial dosage of metoprolol tartrate tablets is 100 mg daily in single or divided doses. Dosage may be increased gradually until optimum blood pressure control is achieved. The effective dosage range is 100 to 450 mg per day. While once-daily dosing is effective and can maintain a reduction in blood pressure throughout the day, lower doses (especially 100 mg) may not maintain a full effect at the end of the 24-hour period, and larger or more frequent daily doses may be required. This can be evaluated by measuring blood pressure near the end of the dosing interval to determine whether satisfactory control is being maintained throughout the day. Beta 1 selectivity diminishes as dosage of metoprolol tartrate tablets is increased. The following dosage schedule may be used to administer from 100 to 200 mg of metoprolol tartrate per day and from 25 to 50 mg of hydrochlorothiazide per day: Metoprolol Tartrate and Hydrochlorothiazide Dosage Tablets of 50/25 2 tablets per day in single or divided doses Tablets of 100/25 1 to 2 tablets per day in single or divided doses Tablets of 100/50 1 tablet per day in single or divided doses Dosing regimens that exceed 50 mg of hydrochlorothiazide per day are not recommended. When necessary, another antihypertensive agent may be added gradually, beginning with 50% of the usual recommended starting dose to avoid an excessive fall in blood pressure.

3 DOSAGE FORMS AND STRENGTHS Metoprolol Tartrate and Hydrochlorothiazide Tablets, USP are available containing 50 mg or 100 mg of metoprolol tartrate, USP and 25 mg or 50 mg of hydrochlorothiazide, USP providing for the following available combinations: 50 mg/25 mg, 100 mg/25 mg or 100 mg/50 mg. • The 50 mg/25 mg tablets are peach, round, scored tablets debossed with M above the score and 424 below the score on one side of the tablet and blank on the other side. • The 100 mg/25 mg tablets are peach, oval, scored tablets debossed with M to the left of the score and 434 to the right of the score on one side of the tablet and blank on the other side. • The 100 mg/50 mg tablets are peach, capsule-shaped, scored tablets debossed with M to the left of the score and 445 to the right of the score on one side of the tablet and blank on the other side. Tablets (metoprolol tartrate/hydrochlorothiazide: 50/25mg; 100/25mg; 100/50mg ( 3 )

4 CONTRAINDICATIONS Metoprolol tartrate and hydrochlorothiazide tablets are contraindicated in patients with: • Cardiogenic shock or decompensated heart failure . • Sinus bradycardia, sick sinus syndrome, and greater than first-degree block unless a permanent pacemaker is in place . • Anuria • Hypersensitivity to metoprolol tartrate or hydrochlorothiazide or to other sulfonamide-derived drugs. • Hypersensitivity to metoprolol tartrate or hydrochlorothiazide or other sulfonamide-derived drugs. ( 4 ) • Cardiogenic shock or decompensated heart failure. ( 4 ) • Sinus bradycardia, sick sinus syndrome, and greater than first-degree block unless a permanent pacemaker is in place. ( 4 ) • Anuria. ( 4 )

ADVERSE REACTIONS Metoprolol Tartrate and Hydrochlorothiazide The following adverse reactions were reported in controlled clinical studies of the combination of metoprolol tartrate and hydrochlorothiazide. Body as a Whole: Fatigue or lethargy and flu syndrome have each been reported in about 10 in 100 patients. Nervous System: Dizziness or vertigo, drowsiness or somnolence, and headache have each occurred in about 10 in 100 patients. Nightmare has occurred in 1 in 100 patients. Cardiovascular: Bradycardia has occurred in about 6 in 100 patients. Decreased exercise tolerance and dyspnea have each occurred in about 1 of 100 patients. Digestive: Diarrhea, digestive disorder, dry mouth, nausea or vomiting, and constipation have each occurred in about 1 in 100 patients. Metabolic and Nutritional: Hypokalemia has occurred in fewer than 10 in 100 patients. Edema, gout, and anorexia have each occurred in 1 in 100 patients. Special Senses: Blurred vision, tinnitus, and earache have each been reported in 1 in 100 patients. Skin: Sweating and purpura have each occurred in 1 in 100 patients. Urogenital: Impotence has occurred in 1 in 100 patients. Musculoskeletal: Muscle pain has occurred in 1 in 100 patients. Metoprolol Most adverse effects have been mild and transient. Central Nervous System: Tiredness and dizziness have occurred in about 10 of 100 patients. Depression has been reported in about 5 of 100 patients. Mental confusion and short-term memory loss have been reported. Headache, nightmares, and insomnia have also been reported, but a drug relationship is not clear. Cardiovascular: Shortness of breath and bradycardia have occurred in approximately 3 of 100 patients. Cold extremities; arterial insufficiency, usually of the Raynaud type; palpitations; and congestive heart failure have been reported. Gangrene in patients with pre-existing severe peripheral circulatory disorders has also been reported very rarely (see CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS). Respiratory: Wheezing (bronchospasm) has been reported in fewer than 1 of 100 patients (see WARNINGS). Rhinitis has also been reported. Gastrointestinal: Diarrhea has occurred in about 5 of 100 patients. Nausea, gastric pain, constipation, flatulence, and heartburn have been reported in 1 of 100, or fewer, patients. Vomiting was a common occurrence. Postmarketing experience reveals very rare reports of hepatitis, jaundice and non-specific hepatic dysfunction. Isolated cases of transaminase, alkaline phosphatase, and lactic dehydrogenase elevations have also been reported. Hypersensitive Reactions: Pruritus has occurred in fewer than 1 of 100 patients. Rash has been reported. Very rarely, photosensitivity and worsening of psoriasis has been reported. Miscellaneous: Peyronie’s disease has been reported in fewer than 1 of 100,000 patients. Alopecia has been reported. There have been very rare reports of weight gain, arthritis, and retroperitoneal fibrosis (relationship to metoprolol has not been definitely established). The oculomucocutaneous syndrome associated with the beta blocker practolol has not been reported with metoprolol. Potential Adverse Reactions A variety of adverse reactions not listed above have been reported with other beta-adrenergic blocking agents and should be considered potential adverse reactions to metoprolol. Central Nervous System: Reversible mental depression progressing to catatonia; visual disturbances; hallucinations; an acute reversible syndrome characterized by disorientation for time and place, short-term memory loss, emotional lability, slightly clouded sensorium, and decreased performance on neuropsychometrics. Cardiovascular: Intensification of AV block (see CONTRAINDICATIONS). Hematologic: Agranulocytosis, nonthrombocytopenic purpura, thrombocytopenic purpura. Hypersensitive Reactions: Fever combined with aching and sore throat, laryngospasm, and respiratory distress. Postmarketing Experience The following adverse reactions have been report …

Drug/Drug Interactions Metoprolol: Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients treated with metoprolol plus a catecholamine depletor should therefore be closely observed for evidence of hypotension or marked bradycardia, which may produce vertigo, syncope, or postural hypotension. Both digitalis glycosides and beta blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia. Risk of Anaphylactic Reaction: While taking beta blockers, patients with a history of severe anaphylactic reaction to a variety of allergens may be more reactive to repeated challenge, either accidental, diagnostic, or therapeutic. Such patients may be unresponsive to the usual doses of epinephrine used to treat allergic reaction. General Anesthetics Some inhalation anesthetics may enhance the cardiodepressant effect of beta blockers (see WARNINGS; Metoprolol; Major Surgery). CYP2D6 Inhibitors Potent inhibitors of the CYP2D6 enzyme may increase the plasma concentration of metoprolol. Strong inhibition of CYP2D6 would mimic the pharmacokinetics of CYP2D6 poor metabolizer. Caution should therefore be exercised when administering potent CYP2D6 inhibitors with metoprolol. Known clinically significant potent inhibitors of CYP2D6 are antidepressants such as fluoxetine, paroxetine or bupropion, antipsychotics such as thioridazine, antiarrhythmics such as quinidine or propafenone, antiretrovirals such as ritonavir, antihistamines such as diphenhydramine, antimalarials such as hydroxychloroquine or quinidine, antifungals such as terbinafine and medications for stomach ulcers such as cimetidine. Clonidine If a patient is treated with clonidine and metoprolol concurrently, and clonidine treatment is to be discontinued, metoprolol should be stopped several days before clonidine is withdrawn. Rebound hypertension that can follow withdrawal of clonidine may be increased in patients receiving concurrent beta blocker treatment. Hydrochlorothiazide: Hypokalemia can sensitize or exaggerate the response of the heart to the toxic effects of digitalis (e.g., increased ventricular irritability). Hypokalemia may develop during concomitant use of steroids or ACTH. Insulin requirements in diabetic patients may be increased, decreased, or unchanged. Thiazides may decrease arterial responsiveness to norepinephrine, but not enough to preclude effectiveness of the pressor agent for therapeutic use. Thiazides may increase the responsiveness to tubocurarine. Lithium renal clearance is reduced by thiazides, increasing the risk of lithium toxicity. There have been rare reports in the literature of hemolytic anemia occurring with the concomitant use of hydrochlorothiazide and methyldopa. Concurrent administration of some nonsteroidal anti-inflammatory agents may reduce the diuretic, natriuretic and antihypertensive effects of thiazide diuretics. Cholestyramine and colestipol resins: Absorption of hydrochlorothiazide is impaired in the presence of anionic exchange resins. Single doses of either cholestyramine or colestipol resins bind the hydrochlorothiazide and reduce its absorption from the gastrointestinal tract by up to 85% and 43%, respectively.

8 USE IN SPECIFIC POPULATIONS • Hepatic Impairment: Consider initiating metoprolol tartrate therapy at low doses and gradually increase dosage to optimize therapy, while monitoring closely for adverse events. ( 8.6 ) 8.1 Pregnancy Risk Summary Untreated hypertension during pregnancy can lead to adverse outcomes for the mother and the fetus (see Clinical Considerations ) . Available data from published observational studies have not demonstrated a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes with metoprolol use during pregnancy. However, there are inconsistent reports of intrauterine growth restriction, preterm birth, and perinatal mortality with maternal use of beta blockers, including metoprolol, during pregnancy (see Data ) . There have been rare reports of jaundice, thrombocytopenia, and electrolyte imbalances in infants exposed to thiazide medications during pregnancy. In animal reproduction studies, metoprolol has been shown to increase post-implantation loss and decrease neonatal survival in rats at oral dosages up to 24 times, on a mg/m 2 basis, the daily dose of 200 mg in a 60-kg patient. The combination of metoprolol tartrate/hydrochlorothiazide administered to rats from mid-late gestation through lactation also produced increased post-implantation loss and decreased neonatal survival (see Data ) . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Consideration Disease-Associated Maternal and/or Embryo/Fetal Risk Hypertension in pregnancy increases the maternal risk for pre-eclampsia, gestational diabetes, premature delivery, and delivery complications (e.g., need for cesarean section, and post-partum hemorrhage). Hypertension increases the fetal risk for intrauterine growth restriction and intrauterine death. Pregnant women with hypertension should be carefully monitored and managed accordingly. Fetal/Neonatal Adverse Reactions Metoprolol Metoprolol crosses the placenta. Neonates born to mothers who are receiving metoprolol during pregnancy, may be at risk for hypotension, hypoglycemia, bradycardia, and respiratory depression. Observe neonates for symptoms of hypotension, bradycardia, hypoglycemia and respiratory depression and manage accordingly. Data Human Data Data from published observational studies did not demonstrate an association of major congenital malformations and use of either metoprolol or hydrochlorothiazide in pregnancy. The published literature has reported inconsistent findings of intrauterine growth retardation, preterm birth and perinatal mortality with maternal use of metoprolol during pregnancy; however, these studies have methodological limitations hindering interpretation. Methodological limitations include retrospective design, concomitant use of other medications, and other unadjusted confounders that may account for the study findings including the underlying disease in the mother. These observational studies cannot definitely establish or exclude any drug-associated risk during pregnancy. Animal Data Oral administration of metoprolol tartrate/hydrochlorothiazide combinations to pregnant rats during organogenesis at doses up to 200/50 mg/kg/day (10 and 20 times the MRHD on a mg/m 2 basis for metoprolol and hydrochlorothiazide, respectively) or to pregnant rabbits at doses up to 25/6.25 mg/kg/day (about 2.5 and 5 times the MRHD on a mg/m 2 basis for metoprolol and hydrochlorothiazide, respectively) produced no teratogenic effects. A 200/50 mg/kg/day metoprolol tartrate/hydrochlorothiazide combination administered to rats from mid-late gestation through lactation produced increased post-implantation loss and decr …

12.1 Mechanism of Action Metoprolol is a beta 1 -selective (cardioselective) adrenergic receptor blocker. This preferential effect is not absolute however, and at higher plasma concentrations, metoprolol also inhibits beta 2 -adrenoreceptors, chiefly located in the bronchial and vascular musculature. Metoprolol has no intrinsic sympathomimetic activity, and membrane-stabilizing activity is detectable only at plasma concentrations much greater than required for beta-blockade. Animal and human experiments indicate that metoprolol slows the sinus rate and decreases AV nodal conduction. The mechanism of the antihypertensive effects of beta-blocking agents has not been elucidated. However, several possible mechanisms have been proposed: (1) competitive antagonism of catecholamines at peripheral (especially cardiac) adrenergic neuron sites, leading to decreased cardiac output; (2) a central effect leading to reduced sympathetic outflow to the periphery; and (3) suppression of renin activity. The mechanism of antihypertensive effect of thiazide diuretics is unknown.

11 DESCRIPTION Metoprolol tartrate and hydrochlorothiazide tablets, USP has the antihypertensive effect of metoprolol tartrate, a beta adrenoreceptor blocker, and hydrochlorothiazide, a thiazide diruetic. It is available as tablets for oral administration. The 50 mg/25 mg tablets contain 50 mg of metoprolol tartrate USP and 25 mg of hydrochlorothiazide USP; the 100 mg/25 mg tablets contain 100 mg of metoprolol tartrate USP and 25 mg of hydrochlorothiazide USP; and the 100 mg/50 mg tablets contain 100 mg of metoprolol tartrate USP and 50 mg of hydrochlorothiazide USP. Metoprolol tartrate USP is (±)-1- (Isopropylamino)-3-[ p -(2-methoxyethyl)phenoxy]-2-propanol L-(+)-tartrate (2:1) salt, and its structural formula is Metoprolol tartrate USP is a white, crystalline powder. It is very soluble in water; freely soluble in methylene chloride, in chloroform, and in alcohol; slightly soluble in acetone; and insoluble in ether. Its molecular weight is 684.82. Hydrochlorothiazide is 6-chloro-3, 4-dihydro-2 H -1,2,4-benzothiadiazine-7- sulfonamide 1,1- dioxide, and its structural formula is Hydrochlorothiazide USP is a white, or practically white, practically odorless, crystalline powder. It is freely soluble in sodium hydroxide solution, in n -butylamine, and in dimethylformamide; sparingly soluble in methanol; slightly soluble in water; and insoluble in ether, in chloroform, and in dilute mineral acids. Its molecular weight is 297.73. Inactive Ingredients: Microcrystalline cellulose, anhydrous lactose, lactose monohydrate, pregelatinized starch, corn starch, compressible sugar, sodium starch glycolate, colloidal silicon dioxide, magnesium stearate, D&C Yellow No. 10 (50 mg/25 mg and 100 mg/50 mg tablets), and FD&C Red No. 40 and FD&C Yellow No. 6 (100 mg/25 mg tablets). metoprolol-chem-str.jpg hctz-chem-str.jpg

OVERDOSAGE Acute Toxicity Several cases of overdosage with metoprolol have been reported, some leading to death. No deaths have been reported with hydrochlorothiazide. Oral LD 50 ’s (mg/kg): mice, 1158 (metoprolol); rats, 3090 (metoprolol), 2750 (hydrochlorothiazide). Signs and Symptoms Metoprolol: Potential signs and symptoms associated with overdosage with metoprolol are bradycardia, hypotension, bronchospasm, and cardiac failure. Hydrochlorothiazide: The most prominent feature of poisoning is acute loss of fluid and electrolytes. Cardiovascular: Tachycardia, hypotension, shock. Neuromuscular: Weakness, confusion, dizziness, cramps of the calf muscles, paresthesia, fatigue, impairment of consciousness. Digestive: Nausea, vomiting, thirst. Renal: Polyuria, oliguria, or anuria (due to hemoconcentration). Laboratory Findings: Hypokalemia, hyponatremia, hypochloremia, alkalosis; increased BUN (especially in patients with renal insufficiency). Combined Poisoning: Signs and symptoms may be aggravated or modified by concomitant intake of antihypertensive medication, barbiturates, curare, digitalis (hypokalemia), corticosteroids, narcotics, or alcohol. Treatment There is no specific antidote. On the basis of the pharmacologic actions of metoprolol tartrate and hydrochlorothiazide, the following general measures should be employed: Elimination of the Drug: Inducement of vomiting, gastric lavage, and activated charcoal. Bradycardia: Atropine should be administered. If there is no response to vagal blockade, isoproterenol should be administered cautiously. Hypotension: The patient’s legs should be elevated and lost fluid and electrolytes (potassium, sodium) should be replaced. A vasopressor should be administered, e.g., levarterenol or dopamine. Bronchospasm: A beta 2 -stimulating agent and/or a theophylline derivative should be administered. Cardiac Failure: A digitalis glycoside and diuretic should be administered. In shock resulting from inadequate cardiac contractility, administration of dobutamine, isoproterenol, or glucagon may be considered. Surveillance: Fluid and electrolyte balance (especially serum potassium) and renal function should be monitored until conditions become normal.

HOW SUPPLIED Metoprolol Tartrate and Hydrochlorothiazide Tablets USP are available containing 50 mg/25 mg, 100 mg/25 mg or 100 mg/50 mg of metoprolol tartrate, USP and hydrochlorothiazide, USP. 50 mg/25 mg tablets are white to off-white colored, round shaped, biconvex, bevel edged scored uncoated tablet debossed with “L” on one side of score line and “230” on another side of score line and plain on other side. NDC 46708-115-30 bottle of 30 tablets NDC 46708-115-31 bottles of 100 tablets NDC 46708-115-91 bottles of 1000 tablets 100 mg/25 mg tablets are white to off-white colored, oval shaped, biconvex, bevel edged scored uncoated tablet debossed with “L” on one side of score line and “232” on another side of score line and plain on other side. NDC 46708-116-30 bottle of 30 tablets NDC 46708-116-31 bottle of 100 tablets NDC 46708-116-71 bottle of 500 tablets 100 mg/50 mg tablets are white to off-white colored, capsule shaped, biconvex, bevel edged scored uncoated tablet debossed with “L” on one side of score line and “231” on another side of score line and plain on other side. NDC 46708-117-30 bottle of 30 tablets NDC 46708-117-31 bottle of 100 tablets NDC 46708-117-71 bottle of 500 tablets Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Protect from moisture. Dispense in tight, light-resistant container (USP). Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. Manufactured by: Alembic Pharmaceuticals Limited (Formulation Division), Village Panelav, P. O. Tajpura, Near Baska, Taluka-Halol, Panchmahal, Gujarat, India. Issued: 02/2016